<script>
import { mapState } from 'vuex'

export default {
  name: 'RankComponent',
  data () {
    return {
      chartInstance: null,
      allData: null,
      startValue: 0, // 区域缩放起点值
      endValue: 9, // 区域缩放终点值
      timerId: null // 定时器id
    }
  },
  mounted () {
    this.initChart()
    // this.getData()
    // 发送数据给服务器
    this.$socket.send({
      action: 'getData',
      socketType: 'RankData',
      chartName: 'rank',
      value: ''
    })

    window.addEventListener('resize', this.screenAdapter)
    this.screenAdapter()
    this.startInterval()
  },
  created () {
    this.$socket.registerCallBack('RankData', this.getData)
  },
  destroyed () {
    window.removeEventListener('resize', this.screenAdapter)
    clearInterval(this.timerId)
    this.$socket.unRegisterCallBack('RankData')
  },
  methods: {
    initChart () {
      this.chartInstance = this.$echarts.init(this.$refs.rank_ref, this.theme)
      const initOption = {
        title: {
          text: '▎ 地区销售排行',
          left: 20,
          top: 20
        },
        grid: {
          top: '40%',
          left: '5%',
          right: '5%',
          bottom: '5%',
          containLabel: true
        },
        tooltip: {
          show: true,
          trigger: 'axis'
        },
        xAxis: {
          type: 'category'
        },
        yAxis: {
          type: 'value'
        },
        series: {
          type: 'bar'
        }
      }
      this.chartInstance.setOption(initOption)
      // 监听鼠标移入图表，自动停止位移
      this.chartInstance.on('mouseover', () => {
        clearInterval(this.timerId)
      })
      // 监听鼠标离开图表，自动开启位移
      this.chartInstance.on('mouseout', () => {
        this.startInterval()
      })
    },
    async getData () {
      // 获取数据
      const { data: ret } = await this.$http.get('rank')
      this.allData = ret
      this.allData.sort((a, b) => {
        return b.value - a.value
      })
      // 给终点赋值
      this.updateChart()
    },
    updateChart () {
      const colorArr = [
        ['#0BA82C', '#4FF778'],
        ['#2E72BF', '#23E5E5'],
        ['#5052EE', '#AB6EE5']
      ]
      // 处理图表需要的数据
      // 所有省份数组
      const provinceArr = this.allData.map((item) => {
        return item.name
      })
      // 所有省份对应的销售金额
      const valueArr = this.allData.map((item) => {
        return item.value
      })
      const dataOption = {
        xAxis: {
          data: provinceArr
        },
        dataZoom: {
          show: false,
          startValue: this.startValue,
          endValue: this.endValue
        },
        series: {
          data: valueArr,
          itemStyle: {
            color: (arg) => {
              let targetColorArr = null
              if (arg.value > 300) {
                targetColorArr = colorArr[0]
              } else if (arg.value > 200) {
                targetColorArr = colorArr[1]
              } else {
                targetColorArr = colorArr[2]
              }
              return new this.$echarts.graphic.LinearGradient(0, 0, 0, 1, [
                {
                  offset: 0,
                  color: targetColorArr[0]
                },
                {
                  offset: 1,
                  color: targetColorArr[1]
                }
              ])
            }
          }
        }
      }
      this.chartInstance.setOption(dataOption)
    },
    screenAdapter () {
      const titleFontSize = (this.$refs.rank_ref.offsetWidth / 100) * 3.6
      const adapterOption = {
        title: {
          textStyle: {
            fontSize: titleFontSize
          }
        },
        series: {
          itemStyle: {
            barBorderRadius: [titleFontSize, titleFontSize, 0, 0],
            barWidth: titleFontSize / 2,
            barHeight: titleFontSize / 2
          }
        }
      }
      this.chartInstance.setOption(adapterOption)
      this.chartInstance.resize()
    },
    startInterval () {
      if (this.timerId) {
        clearInterval(this.timerId)
      }
      this.timerId = setInterval(() => {
        this.startValue++
        this.endValue++
        if (this.endValue > this.allData.length - 1) {
          this.startValue = 0
          this.endValue = 9
        }
        this.updateChart()
      }, 2000)
    }
  },
  computed: {
    ...mapState(['theme'])
  },
  watch: {
    theme () {
      this.chartInstance.dispose() // 销毁当前图表
      this.initChart()
      this.screenAdapter()
      this.updateChart()
    }
  }
}
</script>

<template>
  <div class="com-container">
    <div class="com-chart" ref="rank_ref"></div>
  </div>
</template>

<style scoped></style>
